Question

我有三个查询，我需要将它们合并为一个。有没有人知道怎么做？

select COUNT(*) from dbo.VWAnswer where questionId =2 and answer =1

select COUNT(*) from dbo.VWAnswer where questionId =3 and answer =4

select COUNT(*) from dbo.VWAnswer where questionId =5 and answer =2

我想了解那些gender = 1 and Education = 4 and marital status = 2

的人的总数

以下是我所指的表格列（有一个例子）：

questionId      questionText    anwser    AnserSheetID

  1              Gender           1           1

  2              Qualification    4           1

  3              Marital Status   2           1

  1              Gender           2           2

  2              Qualification    1           2

  3              Marital Status   2           2

  1              Gender           1           3

  2              Qualification    3           3

  3              Marital Status   1           3

基本上，这些问题由不同的人回答，他们的答案存储在此表中。

因此，如果我们考虑上面的表项，我应该根据上述3个条件获得1作为总计数，即gender = 1 and Education = 4 and marital status = 2

有人可以告诉我我需要做些什么才能让它发挥作用吗？

Answer 1

如果要组合三个计数查询，可以尝试使用以下SQL来完成它。

select 
sum(case when questionId =2 and anwser=1 then 1 else 0 end) as FCount,
sum(case when questionId =3 and anwser=4 then 1 else 0 end) as SCount,
sum(case when questionId =5 and anwser=2 then 1 else 0 end) as TCount
from dbo.VWAnswer

更新1：

select 
Sum(case when questionText='Gender' and anwser='1' then 1 else 0 end) as GenderCount,
Sum(case when questionText='Qualification' and anwser='4' then 1 else 0 end) as EducationCount,
Sum(case when questionText='Marital Status' and anwser='2' then 1 else 0 end) as MaritalCount
from VWAnswer

我们只能根据行获取计数，每个条件应适用于每一行。

Answer 2

您可以使用符合条件的联合视图，并选择适合您条件的行数。

Select COUNT(*) as cnt from
(
   Select a.AnserSheetID
   from VWAnswer a
   Join VWAnswer b on a.AnserSheetID=b.AnserSheetID and b.questionId = 2 and b.anwser=4
   Join VWAnswer c on a.AnserSheetID=c.AnserSheetID and c.questionId = 3 and c.anwser=2
   where a.questionId=1 and a.anwser=1
) hlp

如何将多个查询组合到一个查询中

2 个答案: